With Nitrous oxide having many qualities that make it an attractive choice for labor analgesia, many anesthesia providers are questioning its limited use in the United States. It is speculated that it may be cultural issue and that women make decisions regarding labor analgesia based on learned experiences of family and friends, many of whom have not heard of or used nitrous oxide to cope with labor pains. Another reason may be that some authors argue that nitrous oxide is an orphan drug with no pizzazz for professional groups or companies to profit from its use as it causes environmental and occupational hazards which limit its use. No definitive opinion exists to answer this question. Finally, some authors suggest its use is limited due to the disadvantages of nitrous oxide, which include the possibility to cause mood alterations, euphoria, impaired mentation, dysphoria, inappropriate behaviors and nausea and vomiting. These side effects are limited through a number of fail-safe mechanisms built into the nitrous oxide machine which includes the delivery of at least 30% oxygen and 3 liters of fresh gas flow. In addition the proper use includes self administration under direct supervision of a trained provider while the nitrous oxide is in use.